Oh come now. Ever changing maps? Randomly generated holes in the ground? Allowing player made buildings into the main map?
There is no way their servers can handle that load. Not unless they really cap the player count. I mean, imagine 5,000 players fighting 5,000 elementals that destroy 5,000 buildings, all within 2 minutes. The game would have to constantly update player map data. The bandwidth alone would choke them, not to mention the rewriting of the map data every few seconds.
This is a lot of marketing BS that will fail to deliver.